Device for application of fluid

ABSTRACT

Apparatus is disclosed for applying a fluid to a surface and adapted to be mounted on a holder, the apparatus is adjustable in a plurality of directions and includes at least one nozzle which can be rotated by the apparatus. The apparatus includes a feed line for supplying the fluid, a housing for transmitting rotary movement, a rotatable shaft having a longitudinal axis and rotatably mounting the housing, the at least one nozzle mounted on the rotatable shaft, and the feed line is connected to the housing, the housing including a first channel for supplying the fluid from the feed line through the housing, a second channel formed adjacent to the housing for supplying the fluid from the first channel to the rotatable shaft irrespective of the rotatable position of the rotatable shaft, and a third channel arranged at least partially in the rotatable shaft for supplying the fluid from the second channel to the at least one nozzle.

FIELD OF THE INVENTION

The present invention relates to a device for the application of afluid.

BACKGROUND OF THE INVENTION

A current device for the application of a fluid is in practiceimplemented as a rotatable spray gun which has a number of spray nozzlesand is designed to be mounted on a robotic control device.

Spray guns are used when fluids, such as gases, liquids or plasticmaterial, are to be sprayed or extruded onto a surface. One example of afield of application of such a spray gun is in the automobile industry,when bodies are to be surface treated or joints are to be sealed. Otherfields of application are, of course, also possible. When the spray gunis used, it must be positioned carefully in relation to the surface ontowhich the material is to be applied. Conventional spray guns are usuallyfurnished with a single nozzle having a fixed application direction.Redirection of the nozzle must then be carried out by turning the entiregun, which, however, takes considerable time, and can cause problemswith accessibility in confined spaces. Redirection of a spray gun alsoplaces high demands on a robot's control instructions in order toachieve correct application with a high precision.

Rotating spray assemblies with several nozzles are known, for example,from PCT application Ser. No. WO 80/02278. This publication, however,shows a spray assembly with simultaneous feed to all of the nozzles,which severely limits the range of use of the assembly.

One object of the present invention is therefore to improve theaccessibility, such as during extrusion or spraying, which then canproceed without the necessity for a tool change.

A further object of the present invention is to reduce the adjustmenttime which is necessary for an adjustment from a first sprayingdirection to a second spraying direction.

A further object of the present invention is to enable a changeoverbetween different process steps, for example between spraying andextrusion, without an intervening tool change.

SUMMARY OF THE INVENTION

These and other objects have now been accomplished by the discovery ofapparatus for the application of a fluid to a surface and adapted formounting on a holder, the apparatus being adjustable between a pluralityof directions and including at least one nozzle which can be rotatedthereby, the apparatus including feed means for supplying the fluid,swivel means including a housing, a rotatable shaft having alongitudinal axis and rotatably mounting the housing, the at least onenozzle being mounted on the rotatable shaft, the feed means connected tothe housing, and the housing including a first channel for supplying thefluid from the feed means through the housing, a second channel formedadjacent to the housing for supplying the fluid from the first channelto the rotatable shaft irrespective of the rotatable position of therotatable shaft, and a third channel arranged at least partially in therotatable shaft for supplying the fluid from the second channel to theat least one nozzle. Preferably the second channel comprises an annularchannel disposed perpendicularly to the longitudinal axis of therotatable shaft.

In accordance with one embodiment of the apparatus of the presentinvention, the at least one nozzle comprises three nozzles, each of thethree nozzles being aimed in a different direction.

In accordance with another embodiment of the apparatus of the presentinvention, the apparatus includes at least one valve for controlling thesupply of the fluid from the feed means to the at least one nozzle, theat least one valve being mounted on the housing, and being connectedbetween the second channel and the third channel.

In accordance with another embodiment of the apparatus of the presentinvention, the housing includes an inner circumferential surface and thesecond channel comprises an annular channel open towards the innercircumferential surface of the housing.

In accordance with a preferred embodiment of the apparatus of thepresent invention, the housing and the rotatable shaft include acorresponding circumference therebetween, and wherein the third channelcomprises an annular channel for the at least one valve and the at leastone nozzle, the third channel being disposed at the correspondingcircumference between the rotatable shaft and the housing and being opentowards at least part of the corresponding circumference.

In accordance with another embodiment of the apparatus of the presentinvention, the apparatus includes a nozzle head for mounting the atleast one nozzle, and a positioning lance including an extension channelfor each of the at least one valve and each of the at least one nozzlefor supplying the fluid from the rotatable shaft to the nozzle head, thepositioning lance being disposed between the swivel means and the nozzlehead, the swivel means comprising a first module, each of the at leastone valve comprising a second module, the nozzle head comprising a thirdmodule, and the positioning lance comprising a fourth module.

In accordance with the present invention, by means of the possibility ofswitching between different nozzles, the extent of utilization of thedevice can be increased, which leads to reduced process times, and thusreduced production costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail in the followingdetailed description, in which reference is made to the accompanyingdrawings, in which

FIG. 1 is a side, perspective view of the outer construction of a deviceaccording to the present invention with a first nozzle head;

FIG. 2 is a side, elevational, partially sectioned view of anotherdevice according to the present invention, with a second nozzle head;and

FIG. 3 is a side, elevational, enlarged, cross-sectional view through amodule of a swivel means in a device according to the present invention.

DETAILED DESCRIPTION

As is evident from the drawings the device for application of a fluid isdesigned as a gun-shaped tool which comprises five main components,namely an adapter 1 which serves to connect the gun with a robotic arm(not shown), a swivel means 2, which is capable of transmitting a rotarymovement, a connection 3 to a feeder means 4 (see FIG. 2) for a fluid,such as a gas, a liquid or a plastic material, a positioning lance 5 anda head 6 having a number of spray or extrusion nozzles. The constructionand respective function of these different primary components will bedescribed below.

The adapter is constructed to be mounted on a robotic arm of any knowntype, either directly or by means of an intermediate adapter. A roboticarm can usually perform movements in six degrees of freedom, i.e. motionin three directions x, y and z, rotation about first and second axes, yand z, which are perpendicular to each other and which are at a rightangle to the longitudinal direction of the robotic arm, and rotationabout a third axis x which extends in the longitudinal direction of therobotic arm. The adapter 1 transmits the rotary motion about this thirdaxis either because the adapter is rigidly rotated or because a shaft 7located in the adapter is rotated with respect to the adapter. The shaftlocated in the adapter is connected to a shaft 8 rotatably held in theswivel means 2. This shaft can be an integral continuation of the shaft7. In this case, the shafts 7 and 8 consist of a shaft constructed ofone piece, which by means of a locking pin 9 is rotationally fixedlyconnected to the adapter 1 and arranged to be rotated by the roboticarm.

The swivel means 2 is outwardly limited by a housing 10, which has anouter mantle surface 11 and an inner cylindrical wall 12 and two endsurfaces, 13 and 14. The mantle surface of the housing is substantiallycylindrical, but other shapes of the mantle surface of the housing areof course also possible.

A first channel 15 is arranged through the mantle surface of thehousing. The through channel has an inlet opening 16 and an outlet 17.The inlet opening connects the through channel to a supply channel 18,through which the material to be extruded or sprayed is furnished fromthe feed means 4 for the plastic material. The supply channel 18 isformed in the connection means 3, which connects the swivel means 2 tothe feed means 4.

The outlet 17 is connected to a channel 19. This channel runs along theinner wall 20 of the housing 10 and connects the first through channel15 with a number of second through channels 21. The second throughchannels each have an inlet opening 22 and an outlet 23.

The channel 19 is preferably shaped in the form of an annular groove ina bearing ring 24 arranged on the shaft 8. The groove can,alternatively, be milled in the inner wall of the housing.

The groove does not necessarily have to be closed, that is bering-shaped; instead, it is also conceivable to arrange the groove as abranched groove with one or more endings.

Each outlet 23 connects the respective through channel 21 with an inletchannel 25 to a valve means 26. The valve means is maneuverable and canbe opened and closed in some known manner. The valve means consists ofan outlet channel 27 which is connected to an inlet 28 of a channel 29running inside the housing, preferably substantially along thelongitudinal axis of the housing, which coincides with the longitudinalaxis A of the gun.

The channel 29 is, in turn, connected to a channel 30, which runsbetween the inner wall 20 of the housing and the channel 29. The channel30 has an outlet 31, which is connected to a channel 32 which runsannularly around the shaft 8. The channel is partly limited by theperipheral surface 33 of the shaft. The channel is further limited byparts of the structure which rotatably hold the shaft 8 in the housing10. The channel 32 is connected to an inlet 34 which leads to alongitudinal channel 35. This channel, in turn, is possibly connected,as is the case in the shown examples, by means of an extension channel36 and the corresponding channel 42 in the head 6, to an outlet 37 in aspray or extrusion nozzle 38.

The extension channel 36 is formed in the lance 5 which is of a modulartype and can be easily exchanged for a lance of a length which issuitable for the particular desired usage of the tool. The lance 5 isattached to the head 6 and the swivel means 2 in some known manner sothat the head can also be modularly exchanged for heads with othernozzle types, dimensions or locations.

Since the channel 32 runs annularly around the shaft 8, the outlet 31will be in constant communication with the channel 32 during rotation ofthe shaft 8. No interruptions of the supply of material will take placeon account of the rotation.

The spray gun has at least two, and in the example shown in the drawingthree, spray or extrusion nozzles, 38-41. To ensure the functioning ofthe gun, each of the nozzles has a channel between the common channel 19and the nozzle. Each such channel is arranged in a manner correspondingto that of the channel described above with respect to the first nozzle38. To each channel there is also arranged a maneuverable valve means.This implies that each nozzle can be opened and closed independently ofthe others. For this reason, it is possible to open one or more nozzlesat the same time.

The bearing structure preferably comprises a number of ball bearingswhich run in their own grooves milled in the shaft. A number of annularchannels, 32, one for each nozzle, is formed by sealing means 44inserted between the housing and the shaft, which sealing means are incontact with the periphery of the shaft. These means are preferablyfastened in the housing, but it is also conceivable that the rotationtakes place against the inner wall of the housing. The channel 19 canalso be formed through a means 45 inserted between the shaft and thehousing.

The housing is closed axially by first and second end pieces, 46 and 47.

The head of the spray gun is, as has been stated above, arranged with atleast two, for example three, spray or extrusion nozzles, each of whichin the examples shown herein is aiming in different planes and/ordirections. According to the example of FIG. 1, a nozzle is preferablyaimed substantially in the direction of the axis A, i.e. in the xdirection. A second nozzle 38 is preferably aimed substantiallyperpendicular to the longitudinal axis A, i.e. in the y direction. Athird nozzle 40 is aimed in the x/y plane and preferably forms an angleof 40°-50° with the x axis.

In the example shown in FIG. 2, two nozzles, 38 and 39, are illustrated,one of which is aimed axially and the other perpendicularly to thelongitudinal axis A. A third nozzle is hidden behind the head and is,for example, aimed perpendicularly to the other two nozzles, 38 and 39,or forms a smaller or larger angle to one of the other nozzles.

The valve means 26 are, for example, constructed as shown in FIGS. 2 and3 in the form of a ball valve with a valve body in the shape of a ball50 which is urged by a spring 51 to a closed position onto a seat.Opening or closing of the valve is performed using is a control means,which in the example is shown in the form of an axially movable needle57 which is moved by pneumatic means, for example an air controlledpiston 53, movable within an air cylinder 54, which through an air hose(not shown) is connected to a pneumatic control device. Each valve means26 with the corresponding control means, 52, 53 and 54, and channels, 25and 27, is also assembled into a module which is easily replaceable.

The present invention is not restricted to the previous description norto the examples shown in the drawings, but may be varied within thescope of the appended claims. For example, two or more nozzles can havethe same direction of action. The feeding means for the incoming fluidcan have more than one channel for the supply of different fluids. Forexample, air can be added in a separate channel all the way up to aspecial nozzle which has double nozzle holes, e.g. one for each fluid.For each fluid a separate annular channel is required before the valves.Instead of a robotic arm, the gun can be mounted on other types ofmovable holders for automated adjustment between different positionsand/or process steps. The valve means 26 can alternatively be mountedseparated from the swivel means 2 and the gun. The number of nozzles canbe two or more.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

I claim:
 1. Apparatus for the application of a fluid to a surface andadapted for mounting on a holder, said apparatus being adjustablebetween a plurality of directions and including at least one nozzlewhich can be rotated thereby, said apparatus including feed means forsupplying said fluid, swivel means including a housing, a rotatableshaft having a longitudinal axis and rotatably mounting said housing,said at least one nozzle being mounted on said rotatable shaft, saidfeed means connected to said housing, and said housing including a firstchannel for supplying said fluid from said feed means through saidhousing, a second channel formed adjacent to said housing for supplyingsaid fluid from said first channel to said rotatable shaft irrespectiveof the rotatable position of said rotatable shaft, and a third channelarranged at least partially in said rotatable shaft for supplying saidfluid from said second channel to said at least one nozzle.
 2. Theapparatus of claim 1 wherein said second channel comprises an annularchannel disposed perpendicularly to said longitudinal axis of saidrotatable shaft.
 3. The apparatus of claim 1 wherein said at least onenozzle comprises three nozzles, each of said three nozzles being aimedin a different direction.
 4. The apparatus of claim 1 including at leastone valve for controlling the supply of said fluid from said feed meansto said at least one nozzle, said at least one valve being mounted onsaid housing, and being connected between said second channel and saidthird channel.
 5. The apparatus of claim 1 wherein said housing includesan inner circumferential surface and said second channel comprises anannular channel open towards said inner circumferential surface of saidhousing.
 6. The apparatus of claim 4 wherein said housing and saidrotatable shaft include a corresponding circumference therebetween, andwherein said third channel comprises an annular channel for said atleast one valve and said at least one nozzle, said third channel beingdisposed at said corresponding circumference between said rotatableshaft and said housing and being open towards at least part of saidcorresponding circumference.
 7. The apparatus of claim 1 including anozzle head for mounting said at least one nozzle, and a positioninglance including an extension channel for each of said at least one valveand each of said at least one nozzle for supplying said fluid from saidrotatable shaft to said nozzle head, said positioning lance beingdisposed between said swivel means and said nozzle head, said swivelmeans comprising a first module, each of said at least one valvecomprising a second module, said nozzle head comprising a third module,and said positioning lance comprising a fourth module.